In the prior art, it is known to provide car glazings or glass plates with a frame-like profile of a polymer. Specifically, an extrudable polymer adhering to the corresponding prepared glazing surface is extruded directly thereon with the aid of an extrusion die. See, for example, U.S. Pat. Nos. 4,581,276, 4,704,175, 4,571,278, 4,551,372, 4,876,132, 4,938,521, 4,933,032 and German patent nos. 36 27 536 and 38 18 930. Typically, a robot places the extrusion die on an edge of the glazing and moves it along the edge of the glazing. Simultaneously with the movement of the extrusion die, a suitable processor controls a dosing device for the polymer to be extruded The extruded section is then cured and can be used for various purposes.
Typically, the extruded section includes an intermediate body connected to the glazing and to which an assembly adhesive bead has been applied for the assembly of the glazing by an adhesion process. For this purpose, the extruded section advantageously has a channel-like profile cross-section. This channel-like profile, for example, serves as a boundary web for the adhesive bead, preventing any passage of the adhesive material into the field of vision of the glazing when the latter is assembled into the window frame of a car body.
The extruded section can be of the type which is supported against parts of the window frame when the glazing is inserted therein. Consequently, the extruded section further serves to position and fix the glazing when the adhesive bead is cured. Finally, such an extruded section can be in the form of a lip or have a lip which projects outward over the glazing's circumference, closing the gap that remains between the circumferential surface of the glazing and the flange of the window frame that faces the glazing.
A section extruded onto the edge of a glazing can simultaneously fulfill different functions. One embodiment of such an extruded section has a flat-profiled portion with a relatively wide base surface and a lip-like portion projecting outwardly over the glazing's circumference. In this case, the flat-profiled portion serves as an intermediate body for the assembly adhesive bead. The outwardly projecting lip serves as a centering lip when the glazing is inserted in the window frame and as a tightening and decorative lip when the glazing is installed. Glazings pre-equipped with such an extruded section are being used with increasing frequency. (Karl-Heinz Bruck: "Fahrzeugverglasung", Verlag Vieweg, 1990).
In most cases, the process described above provides glazings with an all-round frame that has the same profile cross-section over the entire circumference of the glazing. However, in some cases, it is necessary to provide glazings with an extruded frame, which in specific portions have different profile cross-sections.
One solution has been to provide car glazings with a lip-free, U-profile cross section along its lower horizontal edge, while providing the upper horizontal edge and the two vertical edges with an extruded section which has a lip projecting over the circumference of the glazing. Hitherto, such a frame has been produced in a two process step. In the first step, a first portion of the frame is produced using a first extrusion die and, in the second step, a second portion of the frame is produced with a second extrusion die.
The object of the invention is to provide an apparatus and process for extruding sections of polymer having different profile cross sections with only a single extrusion die.